**Transcription levels of various genes were measured at low temperatures.

+

**This experiment was performed in a chemostat, in contrast to most literature, which used batch cultures.

+

**Transcription levels of various genes were measured at low temperatures.

*The main result of the study revealed that there are large differences in transcription levels in many of the genes between the literature data, that looked at for rapid transitions to cold temperatures, and this study, that looked at long-term low-temperature acclimation.

*The main result of the study revealed that there are large differences in transcription levels in many of the genes between the literature data, that looked at for rapid transitions to cold temperatures, and this study, that looked at long-term low-temperature acclimation.

===Significance===

===Significance===

-

*

+

*The effect of cold temperatures on transcription in yeast has been studied greatly.

**The reduced transcription in the yeast at 12<sup>o</sup>C in the nitrogen limited chemostat indicated there was an over expression of STRE elements.

+

**There was an enrichment of PAC cis-regulatory motifs shown in the analysis of 5 upstream sequences.

+

+

====Figure 3====

+

*The venn diagram shows all the genes that are common to the three previous experiments and the heat map shows the transcription ratios of the 259 common genes.

+

**There is a group of 259 common to three other studies that all responded to the decreased temperatures, but the responses differed.

+

+

====Figure 4====

+

*Venn diagram comparing the genes that were consistently regulated in all three datasets and this study. The heat map compares the 29 genes that were regulated during both adaptation and acclimations studies.

+

**29 genes were regulated in all the studies and only 11 genes showed consistent patterns of regulation in all the studies.

+

**Three of the consistently up-regulated genes are involved in lipid metabolism, suggesting that the cold temperatures affect the fluidity of lipid bilayers.

+

+

====Figure 5====

+

*Venn diagrams comparing the genes that were either up or down regulated in both the acclimation study and adaptation study.

+

**There was very little overlap observed in the growth-rate-responsive genes when the temperature responsive gene datasets of Castrillo and Regenberg were compared with the 139 genes that showed a consistent response to low temperatures.

+

+

====Figure 6====

+

*Venn diagrams of the genes that are specifically up and down regulated in low temperatures comparing them between this study (acclimation) and past studies (adaptation), where ESR genes are identified.

+

**A great overlap was observed when ESR genes were compared with the batch culture genes that were consistently up and down regulated at low temperatures.

Prototrophic: "Strain's that have the same nutritional requirements as the wild-type strain." [[9]]

Supernatant: "The soluble liquid fraction of a sample after centrifugation or precipitation of insoluble solids." [[10]]

Outline

Introduction

Transcriptional regulation was studied in Saccharomyces cerevisiae in response to low temperatures.

This study focused on long-term low-temperature acclimation rather than rapid transitions to low temperature or "cold shock."

This experiment was performed in a chemostat, in contrast to most literature, which used batch cultures.

Transcription levels of various genes were measured at low temperatures.

The main result of the study revealed that there are large differences in transcription levels in many of the genes between the literature data, that looked at for rapid transitions to cold temperatures, and this study, that looked at long-term low-temperature acclimation.

Significance

The effect of cold temperatures on transcription in yeast has been studied greatly.

The studies has always been done in batch cultures.

This study uses a steady-state chemostat model to eliminate the effects of specific growth rates.

Other studies focused on a rapid transition to low temperatures, a cold shock.

This study focuses looks at the effects on yeast transcription with a slow transition to low-temperatures.

This allowed the yeast to acclimate rather than quickly adapt.

These different measures were taken in this experiment so that they could compare their results with the literature data.

The results showed big differences between this study and the literature data.

Table 3

The reduced transcription in the yeast at 12oC in the nitrogen limited chemostat indicated there was an over expression of STRE elements.

There was an enrichment of PAC cis-regulatory motifs shown in the analysis of 5 upstream sequences.

Figure 3

The venn diagram shows all the genes that are common to the three previous experiments and the heat map shows the transcription ratios of the 259 common genes.

There is a group of 259 common to three other studies that all responded to the decreased temperatures, but the responses differed.

Figure 4

Venn diagram comparing the genes that were consistently regulated in all three datasets and this study. The heat map compares the 29 genes that were regulated during both adaptation and acclimations studies.

29 genes were regulated in all the studies and only 11 genes showed consistent patterns of regulation in all the studies.

Three of the consistently up-regulated genes are involved in lipid metabolism, suggesting that the cold temperatures affect the fluidity of lipid bilayers.

Figure 5

Venn diagrams comparing the genes that were either up or down regulated in both the acclimation study and adaptation study.

There was very little overlap observed in the growth-rate-responsive genes when the temperature responsive gene datasets of Castrillo and Regenberg were compared with the 139 genes that showed a consistent response to low temperatures.

Figure 6

Venn diagrams of the genes that are specifically up and down regulated in low temperatures comparing them between this study (acclimation) and past studies (adaptation), where ESR genes are identified.

A great overlap was observed when ESR genes were compared with the batch culture genes that were consistently up and down regulated at low temperatures.